1. Field of the Invention
The present invention relates to metal-ceramic joined articles, particularly, metal-ceramic joined articles wherein a metallic member and a ceramic member are joined together by active brazing metals, and metal-ceramic joined articles with a metallic body wherein a metallic member and a ceramic member are joined by active brazing metals and the metallic body is bonded to the metallic member.
2. Related Art Statement
Heretofore, as one method of joining ceramic members mutually or a metallic member and a ceramic member to each other, a joining method using active brazing metals has been known. In this joining method, superposed foils of alloys containing an active metal such as Ti or Zr, or a foil of such active metal superposed on a foil of metal such as Ni, are sandwiched between surfaces of ceramic members or surfaces of a metallic member and a ceramic member to be joined, and heated to effect joining of the members. For example, U.S. Pat. No. 2,857,663 and Japanese patent application publication No. 12,575/61 disclose a brazing method wherein a foil of a Ti group metal and a foil of Cu or Ni are sandwiched and heated between surfaces of a metallic member and a ceramic member or surfaces of ceramic members to be joined. However, this method has a drawback of low joint strength.
U.S. Pat. No. 4,471,026 discloses ternary alloy solders consisting of Cu, Ti and a metal selected from Ag, Au, Sn or In for brazing ceramic members. Moreover, methods of producing the brazing metals by preliminarily melting three metals to form an alloy thereof, knitting three metal wires together to form a strand, superposing three metal sheets on top of each other, or mixing three metal powders together are also disclosed. However, these methods also have the drawback of a low joint strength.
Japanese patent application laid-open No. 81,071/85 discloses a metal sheet for joining ceramic members, wherein the layer of brazing metal is coated with a layer of active metal. However, this sheet has a shortcoming that the thickness of the active metal layer is too large compared to the thickness of the brazing metal layer, so that a joint of satisfactory strength can not be obtained.